Johannes Ahun, Estonian windsurfer
Johannes Ahun (born 22 December 1987) is an Estonian windsurfer, who specializes in Neil Pryde RS:X discipline. He is also a two-time Olympic sailor, and is currently ranked no. 45 in the world for his class by the International Sailing Federation.Ahun was born in Tallinn, and began surfing at the age of eleven, when he encouraged his father to visit the beach, especially during the winter season. In 2003, he moved to Pirita, where he studied and trained under coach Karmo Kalk, at Hawaii Express Windsurfing School. Two years later, Ahun was admitted to the national senior sailing team, and had been participating in numerous windsurfing competitions, including his official international debut at the 2006 RS:X World Championships in Nago–Torbole, Italy.

Ahun competed for the first time at the 2008 Summer Olympics in Beijing, where he sailed in the men's RS:X windsurfing, finishing in thirty-third place after ten races, with a total of 273 net points. After the Olympics, he gained international success in windsurfing competitions, achieving six top-fifty placements, and narrowly missing out of the medal podium at the 2009 Warnemunder Woche in Warnemünde, Germany. In 2012, Ahun eventually qualified for his second Olympics in London, after placing sixty-second at the 2012 RS:X World Championships in Cadiz, Spain, and receiving an allocated place from the ISAF. He competed in the men's RS:X windsurfing, and improved his sailing performance in all the races. However, he finished only in thirtieth place, with a score of 270 net points, after receiving a discretionary penalty in the fourth race, and for not successfully completing the penultimate race.